Examining Gorse for Invertebrates

[Jason Green]

Hi all,

I've 'discovered' a nice site with Gorse in abundance. The soil nearby is often stony and bare in some parts, and one area I believe had a Stonecrop plant growing.

On paper it looks like a nice site. I don't have any experience of searching these plants for insects, so am hoping any WAB'ers out there have done a similar thing. I'm particularly interested in when the insects will start showing, and the fact that it is already well in flower. Do they continue to use the plant when the flowers die off? The stems and 'leaflets' or whatever they are, look like making it difficult work for invertebrates to navigate. Do you hand-search, beat or sweep for quick sampling?

Thanks in advance!

Take care,

Jason

[aeshna5]

I've always beaten Gorse. You should find plenty of the weevil, Exapion ulicis + there are a couple of Sitona species associated with it, Gorse shieldbugs of course, at least a couple of micro-moths at least associated with it plus plenty of spiders such as Xysticus, Philodromus, etc, ladybird species + I'm sure others.

The shieldbug overwinters as an adult + in this stage best looked for in spring or late summer/early autumn.

[tristanba]

I definitely agree a beating tray is the best approach for gorse - you will find numerous insects on this hostplant and broom is often even more productive.

Lepidoptera to look out for include the tortrix moths Cydia ulicetana (succedana) and Grapholita internana. The first is often particularly common in the spring.

As well as the Gorse Shieldbug, there are several small green mirid species (Asciodema obsoleta and Platycranus bicolor), as well as the lacebug Dictyonota strichnocera which seems to be v uncommon in the London area.

It's worth mentioning that the treehopper Gargara genistae has also recently been reported from gorse; this species is normally confined to stands of broom.

[Jason Green]

Thanks Aesh and Tristan. I tried beating at the time, but the plant seems so spiky and firm it's hard getting the collecting tray underneath sufficiently to catch what comes off! Trial and error I suppose.

I have Broom nearer me than this, so I'll give that a go too.

[Geoff F]

For some reason Gorse never seems to live up to it's promise. Being nearly always in bloom with brilliant yellow flowers I always expect to find more.

Near the coast we get a few spiders on gorse. Agelena labyrinthica becomes common during mid to late summer, although the area is somewhat localised.

And even more localised close to the cliff top is Mangora acalypha.

[Acutipuerilis]

Gorse is fun, but I'm more interested in the stonecrop... There's a tiny black mirid, the stonecrop specialist Chlamydatus evanescens, that was meant to be restricted to northern England and North Wales (and rare in both), but then turned up on someone's roof on the south coast. Bonus points if you can find it!